This disclosure relates to platform attachments in a fan section of a gas turbine engine and methods of securing the platforms to a fan hub.
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
The high pressure turbine drives the high pressure compressor through an outer shaft to form a high spool, and the low pressure turbine drives the low pressure compressor through an inner shaft to form a low spool. The fan section may also be driven by the low inner shaft. A direct drive gas turbine engine includes a fan section driven by the low spool such that the low pressure compressor, low pressure turbine and fan section rotate at a common speed in a common direction.
One type of gas turbine engine includes a fan drive gear system having a fan section with relatively large fan blades. One type of fan section utilizes platforms between adjacent fan blades that are supported by a fan hub to which the fan blades are also secured. Typically, the platforms include seals adhered to platform walls adjacent to the fan blades' exterior airfoil surface. The seals obstruct a gap between the platform and the fan blade to provide a more aerodynamic inner flow path surface by eliminating leakage at the fan blade-platform interface.
One type of platform configuration provides platforms arranged on either side of and integral with each fan blade. Another type of platform is secured the fan hub by a single pin that devises in the platform that cooperate with corresponding lugs in fan hub.